The present invention relates to a dispenser for dispensing a fluid, and more particularly a fluid sample for insertion in a magazine, or some other publication for promotional purposes. The use of a dispenser of the invention is naturally not limited to this use alone, but it does constitute a preferred application for the invention. Therefore, the fluid sample of the invention relates particularly to the fields of perfumes and of cosmetics, for which magazines constitute a major promotional medium.
Since this type of dispenser is made available free of charge, its cost must be particularly low. The component parts of the dispenser and dispenser assembly must be very inexpensive. One known type of sample dispenser has a reservoir containing the fluid and provided with at least one actuating wall on which pressure is exerted, e.g. by means of the thumb, so as to reduce the volume of the reservoir. In addition, the sample is provided with a dispensing orifice via which the fluid is dispensed when the actuating wall is pressed. To improve the quality of the jet of fluid dispensed, it is known that a two-phase spray can be implemented in the form of a mixture of air and of fluid. For this purpose, the reservoir must contain both the fluid and the gas (in general, air). Thus, when the actuating wall is pressed, the fluid is dispensed together with the air, thereby generating a two-phase spray. In addition, that type of sample dispenser is often provided with a removable closure element, e.g. in the form of a tear-off or fold-back tab, for closing off the dispensing orifice, thereby isolating the reservoir from the outside prior to use.
Of the prior art, mention may be made, for example, of Document U.S. Pat. No. 3,897,005 which describes packaging made up of two shells bonded together to define an inside volume which serves as a reservoir. That reservoir is filled with a fluid and with air. In that portion of the reservoir in which the fluid is stored, there is a resilient element (a sort of foam) which locally spaces the two shells apart, even in the state in which it is not yet in use. To actuate that packaging, a corner is torn off, and the shells are pressed together over the resilient element.
When such a sample dispenser is to be inserted inside press publications, e.g. magazines, it is subjected to high pressure due to the weight of the magazines since, in general, they are stored by being stacked up. Thus, the samples situated lowest down are subjected to a pressure corresponding to the total weight of the stack of magazines. Since their reservoirs are filled both with air and with fluid, and since the resilient element can be flattened, there is an obvious risk of a reservoir bursting.
One of the problems addressed by the present invention is thus the ability of the dispenser to withstand pressure.
Another problem addressed by the present invention is to provide a dispenser that is of very small thickness, in particular in its storage condition.
Another problem for the present invention is to provide a dispenser whose actuating wall offers resilience and a return force that are sufficient for it to be actuated by means of a finger, e.g. the thumb.
To this end, the present invention provides a dispenser for dispensing a fluid, said dispenser comprising:
a reservoir containing said fluid and provided with at least one actuating wall on which pressure is exerted to reduce the volume of the reservoir, said reservoir being provided with resilient means suitable for increasing the volume of the reservoir;
a dispensing orifice via which the fluid is dispensed as a mixture with a gas, so as to generate a two-phase spray; and
a removable closure element for closing the dispensing orifice, thereby isolating the reservoir from the outside;
the resilient means being stressed so that the reservoir defines a minimum volume so long as the closure element closes off the dispensing orifice. Thus, the resilient means are not at rest, but rather they store potential energy because they are subjected to stress, usually exerted in the form of deformation.
Thus, prior to removing the closure element, the dispenser is in a configuration that is particularly flat because of the atmospheric pressure that is exerted on the walls of the reservoir so as to flatten it. As soon as the closure element is removed, air can penetrate into the reservoir which is then brought to ambient pressure, thereby enabling the resilient means to relax to a rest position, in which said reservoir defines a maximum volume.
In a first embodiment, the resilient means are defined by the actuating wall which has shape memory enabling it to return to a rest state in which the reservoir defines a maximum volume. In which case, the resilient properties of the actuating wall are used directly. To enable repeated actuating, the actuating wall must have a certain amount of instantaneous shape memory. To enable it to perform the function of resilient means of the invention, it must also have long-term shape memory, since sample dispensers included in magazines can be stored for long periods. That is why the wall must have long-lasting shape memory. The thickness of the dispenser is then determined directly by the thickness of the actuating wall in the fully pushed-in or fully flattened state. As soon as the closure element is removed, the actuating wall returns to its natural state, in which it is possible to actuate it by pushing it in.
In a second embodiment, the resilient means comprise a resilient element disposed inside the reservoir. Advantageously, the resilient element acts on the actuating wall. In which case, the resilient element is an additional part so that the actuating wall does not need to have particular shape-memory capacities.
In addition since the resilient element is stressed to its minimum volume, it is the resilient element that determines the thickness of the dispenser by its own thickness in the fully-compressed state. Thus, the pressure exerted, for example, by a stack of magazines on the walls of the reservoir is not exerted on the fluid inside the reservoir, but rather on the resilient element in its maximally-compressed state. Thus, any risk of the reservoir bursting due to the applied pressure is eliminated because the liquid itself is subjected to almost no pressure. In its fully-compressed configuration, the resilient element then acts as a spacer between the walls of the reservoir so as to define a volume in which the fluid is subjected to almost no pressure. When in the relaxed state, the resilient element is the part with the greatest thickness, and if a sample were to be put in a magazine in this state, it would either be too thick or else it would burst. When it is flattened, it is quite fine. In contrast, as soon as the closure element is removed, air (or more generally gas) can penetrate into the reservoir via the dispensing orifice, so that the resilient element can relax so as to increase the inside volume of the reservoir. It can be said that the reservoir contains almost no fluid so long as the closure element closes off the dispensing orifice. And by filling the dispenser under a vacuum or in an inert atmosphere, it is guaranteed that the fluid stored in the reservoir has never been in contact with the air, thereby protecting it from any damage, e.g. by oxidation.
The dispenser becomes a two-phase spray only after the closure element has been removed, thereby enabling air to enter the reservoir. The dispenser can then be used to release a jet of finely-divided fluid. In addition, the resilient element imparts a certain amount of resilience to the actuating wall that it could not procure by itself. The spring thus performs a function of resisting finger pressure, at the same time as performing a return spring function so as to return the dispenser to its extended initial position.
In a first variant, the resilient element is in the form of a conical spiral spring suitable for being flattened to the thickness of one turn. With a conical spiral spring, it is possible to bring all of the turns into the same plane so that, in the compressed state, the spring is of thickness corresponding to the thickness of a single turn. In the reservoir of the dispenser, the spring then makes it possible to define a volume in which the fluid is not subjected to any pressure.
In a second variant, the resilient element is in the form of a molded plastics part including resilient cross-braces between which a hinged assembly extends that is suitable for being stressed into the same plane as the cross-braces. Preferably, the assembly comprises two legs each connected in hinged manner via one of its ends to a respective one of the resilient cross-braces, and via its other end to a small table-top, so that the table-top can be brought into the same plane as the cross-braces and the legs. This is a second version that is made entirely of plastic, which offers advantages as regards its capacity to be recycled.
The present invention is described more fully below with reference to the accompanying drawings which give an embodiment of the present invention by way of non-limiting example.